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Trends in Amblyopia Risk Factors and Socioeconomic Disparities in Scottish Children Aged 3.5 to 5.5 Years
Miriam L Conway1, Bruce Jw Evans1, Lee Pentland2
1From the Department of Optometry and Visual Science, (M.L.C, B.J.W.E, D.F.E, R.S, B.E.W.E) University of London, London, UK.
Insights
Scotland
Area of Science:
- Ophthalmology and Vision Science
- Public Health
- Pediatric Healthcare
Background:
- Scotland implements a universal, orthoptist-led vision screening program for preschool children (ages 3.5-5.5 years).
- The program screens approximately 45,000 children annually, achieving an 85% participation rate.
- Screening involves tests for presenting vision, cover test, and other orthoptic evaluations, with failures referred for comprehensive eye exams.
Purpose of the Study:
- To determine the prevalence of amblyopia risk factors (ARFs) in Scottish children aged 3.5-5.5 years.
- To explore potential associations between ARFs and socioeconomic factors like deprivation, housing, and location.
- To assess the effectiveness and equity of the national vision screening program.
Main Methods:
- A retrospective cohort and trend study analyzed data from Scottish Health Boards covering 87% of the population.
- Data spanned multiple school years (2013/14, 2014/15, 2015/16, 2020/21, 2021/22).
- Amblyopia risk factors included constant manifest strabismus, significant hyperopia, astigmatism, and anisometropia, identified through refractive error and cover test results.
Main Results:
- The prevalence of at least one ARF ranged from 4.41% to 5.15% across the studied years, with no significant temporal trend.
- In 2021-22, astigmatism was the most common ARF (48.23%), followed by hyperopia (35.10%) and strabismus (13.73%).
- No significant correlations were found between ARFs and deprivation, housing, or location; however, children in the most deprived quintile were significantly more likely to fail screening (39-60% higher odds).
Conclusions:
- The study validates the importance of Scotland's universal vision screening program, identifying approximately 5% of young children with ARFs.
- Children from the most deprived areas face a higher likelihood of failing vision screening, highlighting potential disparities.
- Further investigation into the socioeconomic determinants of vision impairment and screening outcomes is warranted.
Objective:
Scotland's comprehensive orthoptist-led vision screening program for children (3.5-5.5 years) has participation of ∼85% (∼45,000 annually). Tests include presenting vision, cover test, and other orthoptic evaluations. Screening failures are referred for an eye examination, including cycloplegic refraction, by an optometrist/ophthalmologist.
Primary Objectives:
report prevalence of amblyopia risk factors (ARFs) in a defined population.
Secondary Objective:
investigate associations between ARFs and deprivation/housing/location.
Design:
Retrospective cohort and trend study.
Participants:
Scottish children aged 3.5 to 5.5 years.
Methods:
ARFs considered were constant manifest strabismus, hyperopia (spherical equivalent refraction, SER) >+4.00D (one/both eyes), astigmatism >1.75DC (one/both eyes), anisometropia >1.25DC for astigmatism and >1.25D (SER) for hyperopic or mixed anisometropia. Data are from 2013/14, 2014/15, 2015/16, 2020/21, and 2021/22 school years, from Health Boards containing 87% of Scotland's population.
Main Outcome Measures:
Refractive error and cover test results.
Results:
Prevalence (95% CI) of ≥ one ARF ranged from 4.41% (4.21-4.60, 2013-14) to 5.15% (4.92-5.38, 2021-22), with no statistically significant relationship between prevalence of any ARF and time (for Bonferroni corrected adjusted P-value = .008). In 2021 to 22, for children with ≥1 ARF, 48.23% had astigmatism, 35.10% hyperopia (SER), 26.59% hyperopic anisometropia (SER), 13.73% constant manifest strabismus and 12.64% astigmatic anisometropia. Correlations between ARFs and deprivation/housing/location were not significant (P = .06 to 1.00). For all years, odds ratios for referral following screening failure in quintile 1 (most deprived) were significantly higher (39% to 60% higher, P < .001) than middle quintile 3.
Conclusions:
In this Scottish population (3.5 to 5.5 years) the prevalence of children with ≥1 ARF was approximately 5%, validating the universal vision screening program's importance. Children in the most deprived quintile were significantly more likely to fail screening.
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